Issue #145: Dump the coin_data table for debugging purposes

Added coinlog command which is called this way:

./ngccc-cli.py coinlog

This will output data from the coin_data table like this:

--------------------------
bitcoin
--------------------------
<address> <txhash>:<outindex> <satoshi value> <confirm status>
...
--------------------------
<another color>
-------------------------
...
...
Merge pull request #150 from jimmysong/145

Issue #145: Dump the coin_data table for debugging purposes